We are now running thousands of assays versus hundreds before.

Riccardo Russo, Ph.D.

Lab Manager, Rutgers Medical School Division of Infectious Diseases

Echo Liquid Handler Assists Rutgers Researchers to Fight Future Infections via Accelerated Antibiotic Discovery

In his work as a researcher at Rutgers University, Dr. Riccardo Russo wears many hats - and often a hazmat suit.

Dr. Russo is the manager of the in vitro screening Core Laboratory directed by Dr. Nancy Connell at Rutgers Medical School’s Division of Infectious Diseases and its Biosafety Level 3 Containment Laboratory, as well as a senior scientist who conducts his own research.


Accelerating the Discovery of New Antimicrobial Compounds

with Dr. Riccardo Russo

Dr. Riccardo Russo of Rutgers University discusses the importance of speeding up the discovery of new antibiotics in an environment of increasing occurrences of multidrug resistant (MDR) bacteria. He explores how automation and miniaturization of samples are critical in the antibiotic development process and how they significantly decrease the amounts of drugs and reagents needed.

About the Research

The main focus of their work is the discovery of new antibiotics against high-threat pathogens. At a time when multidrug resistant (MDR) bacteria is on the rise, Drs. Connell and Russo are always on the lookout for anything that might speed up this process and lead to potential therapeutic candidates. In this regard, the Echo Liquid Handler has been a godsend.

Automation and the miniaturization of samples have saved him hundreds of hours and dollars. They have also expanded the capabilities and accuracy of critical tests performed in the labs.

The Echo has been very useful because we have been able to use much lower volumes of our compounds. Since the instrument is using acoustic waves to dispense different amounts of compound, we avoid the problem of compounds sticking to tips or the wall of the wells, and we have saved a lot of supplies.

Echo 555 Liquid Handler

One of the cornerstone tests conducted in their labs is the Minimal Inhibitory Concentration (MIC) assay. This test is done at the very beginning of the antimicrobial compound discovery process, to determine the lowest concentration of a compound that kills or inhibits visible growth of a bacterium.

It requires serial dilution of the compounds into liquid wells, a process that can take a few hours for manually testing several compounds. By switching to automated acoustic handling and 384-well plates, now it takes a few minutes to assay several compounds.

“We are now running thousands of assays versus hundreds before,” Dr. Russo said.

Perhaps more importantly, the contact-less process reduces the risk of compound carry-over, which can skew results and lead to miscalculations of MIC. This, in turn, could interfere with the proper design of future animal studies.

Another important test conducted in the Rutgers labs is the synergy assay. This test is similar to the MIC assay, but two or more compounds are diluted at the same time, in order to test potential drug combinations and their effect on difficult-to-treat or multi-drug resistant bacteria. It is more time consuming and more prone to errors, so the automation and accuracy of the Echo system have been especially welcome.

We have found that with the Echo instrument, we are able to prepare more plates for synergy assays and there is less problem of error rates as the plates are prepared by the machine. With the Echo, we are able to prepare eight to ten 384-well plates in 1 hour. It would take 20 to 24 hours work to prepare the same amount of plates manually. So, it has been a big advantage for us, and we are now able to regularly run synergy assays, whereas before we were just running some occasionally.

In order to determine whether compounds are actually killing the bacteria or just inhibiting its growth, Dr. Russo runs yet another test, the Minimal Bactericidal Concentration (MBC) assay, which measures the concentration of bacteria in liquid cultures reported as Colony Forming Units (CFUs). For this assay, the ability of the Echo system to dispense different amounts of several bacterial cultures is especially helpful, since this assay requires preparation of up to ten dilutions of each sample. It has also reduced prep time from four hours to just eight minutes.

Dr. Russo has realized that adopting the Echo system has resulted in significant savings, and he is eager to apply it to other tests, such as the mammalian cytotoxicity test and the intracellular MIC assay used to determine which concentration of drug is needed to kill or to inhibit the growth of bacteria inside mammalian cells.